Visual display with electro-optical individual pixel addressing architecture

ABSTRACT

A display device and method of operating the display device. The display device comprising a support substrate, a plurality of light emitting light emitting resonators placed in a matrix on the support substrate forming a plurality of rows and columns of the light emitting resonators, a plurality of light waveguides positioned on the substrate such that each of the light emitting resonators is associated with an electro-coupling region with respect with to one of the plurality of light waveguides, a deflection mechanism for causing relative movement between a portion of at least one of the plurality of light waveguides and the associated light emitting resonator so as to individually control when each of the light emitting resonator is in the electro-coupling region, and a light source associated with each of the plurality of light waveguides for transmitting a light along the plurality of light waveguides for selectively activating each of the light emitting resonators when positioned within the electro-coupling region.

CROSS REFERENCE TO RELATED APPLICATIONS

U.S. Ser. No. 11/095,167, filed Mar. 31, 2005, of John P. Spoonhower,and David Lynn Patton entitled “Visual Display With Electro-OpticalAddressing Architecture”;

U.S. Ser. No. 11/096,031, filed Mar. 31, 2005, of John P. Spoonhower andDavid Lynn Patton, entitled “Polarized Light Emitting Source With AnElectro-Optical Addressing Architecture”;

U.S. Ser. No. 11/094,855, filed Mar. 31, 2005, of John P. Spoonhower,and David Lynn Patton entitled “Placement Of Lumiphores Within A LightEmitting Resonator In A Visual Display With Electro-Optical AddressingArchitecture”.

FIELD OF THE INVENTION

A flat panel visible display wherein optical waveguides and other thinfilm structures are used to distribute (address) excitation light to apatterned array of visible light emitting pixels.

BACKGROUND OF THE INVENTION

A flat panel display system is based on the generation ofphoto-luminescence within a light cavity structure. Optical power isdelivered to the light emissive pixels in a controlled fashion throughthe use of optical waveguides and a novel addressing scheme employingMicro-Electro-Mechanical Systems (MEMS) devices. The energy efficiencyof the display results from employing efficient, innovativephoto-luminescent species in the emissive pixels and from an opticalcavity architecture, which enhances the excitation processes operatinginside the pixel. The present system is thin, light weight, powerefficient and cost competitive to produce when compared to existingtechnologies. Further advantages realized by the present system includehigh readability in varying lighting conditions; high color gamut;viewing angle independence, size scalability without brightness andcolor quality sacrifice, rugged solid-state construction, vibrationinsensitivity and size independence. The present invention has potentialapplications in military, personal computing and digital HDTV systems,multi-media, medical and broadband imaging displays and large-screendisplay systems. Defense applications may range from full-color,high-resolution, see-through binocular displays to 60-inch diagonaldigital command center displays. The new display system employs thephysical phenomena of photo-luminescence in a flat-panel display system.

Previously, Newsome disclosed the use of upconverting phosphors andoptical matrix addressing scheme to produce a visible display in U.S.Pat. No. 6,028,977. Upconverting phosphors are excited by infraredlight; this method of visible light generation is typically lessefficient than downconversion (luminescent) methods like directfluorescence or phosphorescence, to produce visible light. Furthermore,the present invention differs from the prior art in that a differentaddressing scheme is employed to activate light emission from aparticular emissive pixel. The method and device disclosed herein doesnot require that two optical waveguides intersect at each light emissivepixel. Furthermore, novel optical cavity structures, in the form ofoptical light emitting resonators, are disclosed for the emissive pixelsin the present invention.

Additionally, in US Patent Application Publication No. US2002/0003928A1,Bischel et al. discloses a number of structures for coupling light fromthe optical waveguide to a radiating pixel element. The use ofreflective structures to redirect some of the excitation energy to theemissive medium is disclosed. In the present invention, we disclose theuse of novel optical cavity structures, in the form of ring or diskresonators, the resonators themselves modified to affect the emission ofvisible light.

The use of such resonators further allows for a novel method of controlof the emission intensity, through the use of Micro-Electro-MechanicalSystems (MEMS) devices to alter the degree of power coupling between thelight power delivering waveguide and the emissive resonator pixel. Suchmeans have been disclosed in control of the power coupling toopto-electronic filters for telecommunications applications. In thiscase, the control function is used to tune the filter. Control over thepower coupling is described in “A MEMS-Actuated Tunable MicrodiskResonator”, by Ming-Chang M. Lee and Ming C. Wu, paper MC3, 2003IEEE/LEOS International Conference on Optical MEMS, 18–21 Aug. 2003.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention there is provideda display device, comprising:

a. a support substrate;

b. a plurality of light emitting resonators placed in a matrix on saidsupport substrate forming a plurality of rows and columns of said lightemitting resonators;

c. a plurality of light waveguides positioned on said substrate suchthat each of said light emitting resonators is associated with anelectro-coupling region with respect with to one of said plurality oflight waveguides;

d. a deflection mechanism for causing relative movement between aportion of at least one of said plurality of light waveguides and saidassociated light emitting resonator so as to individual control wheneach of said light emitting resonator is in said electro-couplingregion, said deflection mechanism comprises pairs of electrodesassociated with each of said plurality of light emitting resonators andan triggering electrode associated with each of said pairs of electrodesfor selecting deflecting a portion of said waveguide associated with oneof said plurality of light emitting resonators whereby when a voltage isapplied across said pair of electrodes and said triggering electrodesassociated with said selected resonator that field is produced whichcaused said at least one waveguide to move into said electro-couplingregion; and

e. a light source associated with each of said plurality of lightwaveguides for transmitting a light along said plurality of lightwaveguides for selectively activating each of said light emittingresonators when positioned within said electro-coupling region.

In accordance with another aspect of the present invention there isprovided a method for controlling visible light emitting from a displaydevice having plurality of light emitting resonators placed in a patternforming a plurality of rows and columns and a plurality of wave lightguides positioned so that each of said light emitting resonators ispositioned adjacent one of said plurality of wave light guides;comprising the steps of:

a. providing a light source associated with each of said plurality oflight waveguides for transmitting a light along said associated lightwaveguide;

b. providing deflection mechanism for causing selective individualrelative movement between a portion of at least one of said plurality oflight waveguides and one of said associated light emitting resonator soas to selectively control when each of said light emitting resonator isin said electro-coupling region; and

c. selectively controlling emission of visible light from said pluralityof light emitting resonators by controlling said deflection mechanismand light source such that when said light emitting resonator in saidelectro-coupling region and a light is transmitted along said associatedlight waveguide said emission of visible light will occur; and

d. a control mechanism is provided for controlling the amount of voltageacross said pair of electrodes and said triggering electrodes so as tocontrol the distance in which said at least one waveguide moves intosaid electro-coupling region so as to control the amount of emissionfrom said associated light emitting resonator.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features, and advantages of the presentinvention will become more apparent when taken in conjunction with thefollowing description and drawings wherein identical reference numeralshave been used, where possible, to designate identical features that arecommon to the figures, and wherein:

FIG. 1 is a schematic top view of an optical flat panel display made inaccordance with the present invention;

FIG. 2 is an enlarged top plan view of the light emitting resonators forthe display of FIG. 1 made in accordance with the present invention;

FIG. 3 is enlarged top plan views of the red light, green light and bluelight emitting resonators for a color display 1 made in accordance withthe present invention;

FIG. 4 is an enlarged cross-sectional view of the optical waveguide astaken along line 4—4 of FIG. 3;

FIG. 5 is an enlarged cross-sectional schematic view of the opticalwaveguide showing the electrode geometry and electrostatic forces;

FIG. 6 is an enlarged perspective view of a portion of the display ofFIG. 1 showing a single ring resonator; single associated opticalwaveguide and electrodes;

FIGS. 7A, B and C are enlarged cross-sectional view of the display ofFIG. 6 taken along line 7—7 of FIG. 6, which shows the location of aMEMS device used to control the pixel intensity at various intensitypositions;

FIG. 8 is an enlarged cross-sectional view of the waveguide andresonator elements showing an alternative embodiment for thelight-emissive resonator, and

FIG. 9 is an enlarged top plan view showing an alternative resonatorembodiment in the form of a disk.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1–2 there is illustrated a photo-luminescent display5 system made in accordance with the present invention. The displaysystem functions by converting excitation light to emitted, visiblelight. In the embodiment illustrated each pixel 10 in display 5 iscomprised of one or more sub-pixels; sub-pixels are typically comprisedof a red sub-pixel 11, a green sub-pixel 12, and a blue sub-pixel 13, asshown in FIG. 3. Colors other than red, green, and blue are caused bythe admixture of these primary colors; thus controlling the intensity ofthe individual sub-pixels adjusts both the brightness and color of apixel 10. Those skilled in the art understand that other primary colorselections are possible and will lead to a full color display. Colorgeneration in the display is a consequence of the mixing ofmultiple-wavelength light emissions by the viewer. This mixing isaccomplished by the viewer's integration of spatially distinct,differing wavelength light emissions from separate sub-pixels that arebelow the spatial resolution limit of the viewer's eye. Typically acolor display has red, green, and blue separate and distinct sub-pixels,comprising a single variable color pixel. Monochrome displays may beproduced by the use of a single color pixel 10 or sub-pixel (11,12, 13),or by constructing a single pixel capable of emitting “white” light. Thespectral characteristics of a monochrome display pixel will bedetermined by the choice of lumiphore or combination of lumiphores.White light generation can be accomplished through the use of multipledoping schemes for the light emitting resonator 30 as described byHatwar and Young in U.S. Pat. No. 6,727,644 B2. Photo-luminescence isused to produce the separate wavelength emission from each pixel (orsubpixel) element. The photo-luminescence may be a result of a number ofphysically different processes including, multi-step, photonicup-conversion processes and the subsequent radiative emission process,direct optical absorption and the subsequent radiative emission process,or optical absorption followed by one or more energy transfer steps, andfinally, the subsequent radiative emission process. Use of combinationsof these processes may also be considered to be within the scope of thisinvention.

Referring now to FIGS. 1 and 2, FIG. 1 is schematic top view of anoptical flat panel display 5 made in accordance with the presentinvention and FIG. 2 is and enlarged top view of a portion of FIG. 1.The display 5 contains an array 7 of light emitters comprised of amatrix of pixels 10 each having a light emitting resonator 30 (shown inFIG. 3) located at each intersection of an optical row waveguide 25 androws 23 comprising triggering electrodes 24 _(1-n) and column electrodes28. A power source 22 is used to activate the light source array 15. Thelight source array 15 provides optical power or light 20, used to excitethe photo-luminescent process in each pixel 10. Typical light sourcearray elements 17 may be diode lasers, infrared laser, light emittingdiodes (LEDs), and the like. These may be coherent or incoherent lightsources. There may be a one-to-one correspondence between the lightsource array element 17, and an optical row waveguide 25, oralternatively, there may be a single light source array element 17multiplexed onto a number of optical row waveguides 25, through the useof an optical switch to redirect the light 20 output from the singlelight source array element 17.

A principal component of the photo-luminescent flat panel display system5 is the optical row waveguide 25, also known as a dielectric waveguide.Two key functions are provided by the waveguides 25. They confine andguide the optical power to the pixel 10. Several channel waveguidestructures have been illustrated in US patent application U.S. Pat. No.6,028,977. The optical waveguides must be restricted to TM and TEpropagation modes. TM and TE mode means that optical field orientationis perpendicular to the direction of propagation. Dielectric waveguidesconfining the optical signal in this manner are called channelwaveguides. The buried channel and embedded strip guides are applicableto the proposed display technology. Each waveguide consists of acombination of cladding and core layer. These layers are fabricated oneither a glass-based or polymer-based substrate. The core has arefractive index greater than the cladding layer. The core guides theoptical power past the resonator in the absence of power coupling. Withthe appropriate adjustment of the distance between the optical rowwaveguide 25 and the light emitting resonator 30, power is coupled intothe light emitting resonator 30. At the light emitting resonator 30 thecoupled optical light power drives the resonator materials into aluminescent state. The waveguides 25 and resonators 30 can be fabricatedusing a variety of conventional techniques including microelectronictechniques like lithography. These methods are described, for example,in “High-Finesse Laterally Coupled Single-Mode BenzocyclobuteneMicroring Resonators” by W.-Y. Chen, R. Grover, T. A. Ibrahim, V. Van,W. N. Herman, and P.-T. Ho, IEEE Photonics Technology Letters, 16(2), p.470. Other low-cost techniques for the fabrication of polymer waveguidescan be used such as imprinting, and the like. Nano-imprinting methodshave been described in “Polymer Microring Resonators Fabricated ByNanoimprint Technique” by Chung-yen Chao and L. Jay Gao, J. Vac. Sci.Technol. B 20(6), p. 2862. Photobleaching Of Polymeric Materials As AFabrication Method has been described by Joyce K. S. Poon, Yanyi Huang,George T. Paloczi, and Amnon Yariv, in “Wide-Range Tuning Of PolymerMicroring Resonators By The Photobleaching Of CLD-1 Chromophores” by,Optics Letters 29(22), p. 2584. This is an effective method for postfabrication treatment of optical micro-resonators. A wide variety ofpolymer materials are useful in this and similar applications. Thesescan include fluorinated polymers, polymethylacrylate, liquid crystalpolymers, and conductive polymers such as polyethylene dioxythiophene,polyvinyl alcohol, and the like. These materials and additionally thosein the class of liquid crystal polymers are suitable for thisapplication (see “Liquid Crystal Polymer (LCP) for MEMs”, by X. Wang et.al., J. Micromech. MicroEng, 13, (2003), p. 628–633.) This list is notintended to be all inclusive of the materials that may be employed forthis application.

Excitation of the light emitting resonator 30 (shown in FIG. 3) by therow waveguide 25 under the control of the column voltage source 18 rowand column 28 individual triggering electrodes 24 _(1-n) respectivelycauses the light emitting resonator 30 to emit visible light. Theexcitation of the light emitting resonator 30 is caused by opticalpumping action of the light 20 shown in FIG. 1 from a row light sourcearray element 17 through the row waveguide 25 and controlling voltage tothe row 28 and triggering electrodes 24 _(1-n) and controller 19 from acolumn voltage source 18. The excitation process is a coordinatedrow-column, electrically activated, optical pumping process calledelectro-optical addressing. Those skilled in the art know that the rolesof columns and rows are fully interchangeable without affecting theperformance of this display 5.

Now referring to FIG. 3, electro-optical addressing is defined as amethod for controlling an array 7 (not shown) of light emittingresonators 30 that form the optical flat panel display 5 (see FIG. 1).In FIG. 2, a pixel 10 comprised of 3 sub-pixels, 11, 12, and 13 isshown. In electro-optical addressing, the selection of a particularpixel that appears to be light emitting is accomplished by the specificcombination of excitation of light in a particular optical row waveguide25, and voltage applied to a selected individual light emittingresonators 30.

The light emitting resonator 30 is excited into a photo-luminescentstate through the absorption of light 20 as a result of the closeproximity to the row waveguides 25. The physics of the coupling ofenergy between the resonator 30 and the optical row waveguide 25 is wellknown in the art. It is known to depend critically upon the optical pathlength between the row waveguide 25 and the light emitting resonator 30;it can therefore be controlled by the distance (h, shown in FIGS. 7A and7B) separating the two structures or by various methods of controllingthe index of refraction. Typical methods for control of the index ofrefraction include heat, light, and electrical means; these are wellknown. These methods correspond respectively to the thermo-optic,photorefractive, and electro-optic methods. The invention disclosedherein makes use of control of the distance parameter via a MEMS deviceto control the energy coupling, and thus affect the intensity ofphoto-luminescent light generated in the pixel 10. In an example, thelight emitting resonator 30 is composed of a light transmissive materialbut incorporating (doped with) a light emitting photo-luminescentspecies. The base material (the material excluding the photo-luminescentspecies or dopant) for the light emitting resonator may be the same ordifferent from the optical row waveguide 25 material. Typical basematerials can include glasses, semiconductors, or polymers.

Photo-luminescent species or dopants can include various fluorophores,or phosphors including up-converting phosphors. The selection of aparticular dopant or dopants will primarily determine the emissionspectrum of a particular light emitting resonator 30. These lumiphores(fluorophores or phosphors) may be inorganic materials or organicmaterials. The light emitting resonator 30 can include a combination ofdopants that cause it to respond to the electro-optic addressing byemitting visible radiation. Dopant or dopants include the rare earth andtransition metal ions either singly or in combinations, organic dyes,light emitting polymers, or materials used to make Organic LightEmitting Diodes (OLEDs). Additionally, lumiphores can include suchhighly luminescent materials such as inorganic chemical quantum dots,such as nano-sized CdSe or CdTe, or organic nano-structured materialssuch as the fluorescent silica-based nanoparticles disclosed in U.S.Patent Application Publication US 2004/0101822 A1 by Wiesner and Ow. Theuse of such materials is known in the art to produce highly luminescentmaterials. Single rare earth dopants that can be used are erbium (Er),holmium, thulium, praseodymium, neodymium (Nd) and ytterbium. Somerare-earth co-dopant combinations include ytterbium: erbium, ytterbium:thulium and thulium: praseodymium. Single transition metal dopants arechromium (Cr), thallium (Tl), manganese (Mn), vanadium (V), iron (Fe),cobalt (Co) and nickel (Ni). Other transition metal co-dopantcombinations include Cr:Nd and Cr:Er. The up-conversion process has beendemonstrated in several transparent fluoride crystals and glasses dopedwith a variety of rare-earth ions. In particular, CaF₂ doped with Er³⁺.In this instance, infrared upconversion of the Er3+ ion can be caused toemit two different colors: red (650 nm) and green (550 nm). The emissionof the system is spontaneous and isotropic with respect to direction.Organic fluorophores can include dyes such as Rhodamine B, and the like.Such dyes are well known having been applied to the fabrication oforganic dye lasers for many years. The preferred organic material forthe light emitting resonator 30 is a small-molecular weight organichost-dopant combination typically deposited by high-vacuum thermalevaporation. It is also preferred that the host materials used in thepresent invention are selected such that they have sufficient absorptionof the excitation light 20 and are able to transfer a large percentageof their excitation energy to a dopant material via Förster energytransfer. Those skilled in the art are familiar with the concept ofFörster energy transfer, which involves a radiationless transfer ofenergy between the host and dopant molecules. An example of a usefulhost-dopant combination for red-emitting lasers is aluminumtris(8-hydroxyquinoline) (Alq) as the host and[4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran](DCJTB) as the dopant (at a volume fraction of 1%). Other host-dopantcombinations can be used for other wavelength emissions. For example, inthe green a useful combination is Alq as the host and[10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,11H-[1]Benzopyrano[6,7,8-ij]quinolizin-11-one](C545T) as the dopant (at a volume fraction of 0.5%). Other organiclight emitting materials can be polymeric substances, e.g.,polyphenylenevinylene derivatives, dialkoxy-polyphenylenevinylenes,poly-para-phenylene derivatives, and polyfluorene derivatives, as taughtby Wolk et al. in commonly assigned U.S. Pat. No. 6,194,119 B1 andreferences therein.

Electro-optical addressing employs the optical row waveguide 25 todeliver light 20 to a selected light emitting resonator 30. The lightemitting resonator 30 is the basic building block of the optical flatpanel display 5. Referring again to FIG. 3 an enlarged top view of a redlight 41, green light 42 and blue light 43 light emitting resonator 30respectively, is illustrated. Using the red light 41, green light 42 andblue light 43 light emitting resonators to create red 11, green 12, andblue 13 pixels, a full color optical flat panel display 5 can be formed.The wavelength of the emission of the red, green and blue (41–43) lightis controlled by the type of material used in forming the light emittingresonators 30. Selection of a particular pixel 10 or sub-pixel (11–13)is based upon the use of a MEMS device to alter the distance and affectthe degree of power transfer of light 20 to the light emitting resonator30. Note that in each instance, light 20 is directed within anappropriate optical row waveguide 25 to excite a particular lightemitting resonator 30. Through the combination of excitation specificoptical row waveguide with light 20 and excitation of a specific MEMSdevice, controlled by energizing one of the triggering electrodes 24_(1-n) and one of the rows 28, a particular pixel 10 (subpixel) isexcited. The light emitting resonator 30 may take the form of amicro-ring or a micro-disk. These forms are shown in FIGS. 3, and 9,respectively. Note that in order for the light emitting resonator 30 toproduce sufficient light to be viewable, the resonator 30 must befabricated in a manner so that it is “leaky”; there are a number ofmethods to accomplish this lowering of the cavity Q, including but notlimited to increasing the surface roughness of the resonator cavitysurface. Additionally, one could lower the refractive index of thematerial comprising the light emitting resonator 30.

The substrate or support 45 (see FIG. 4) can be constructed of either asilicon, glass or a polymer-based substrate material. A number of glassand polymer substrate materials are either commercially available orreadily fabricated for this application. Such glass materials include:silicates, germanium oxide, zirconium fluoride, barium fluoride,strontium fluoride, lithium fluoride, and yttrium aluminum garnetglasses. A schematic of an enlarged cross-sectional view of the opticalflat panel display 5 taken along the line 4—4 of FIG. 3 is shown in FIG.4. The individual triggering electrodes 24 _(1-n) and column electrodes28 are not shown for simplicity. On a substrate 45 is formed a layer 35containing the optical row waveguide 25 and the light emittingresonator. For such a buried channel waveguide structure it isimperative that the refractive index of optical row waveguide 25 (thecore) be greater than the surrounding materials, in this instance thelayer 35. The layer 35 acts as the cladding region in this embodiment.An optional layer 32 is shown, this may be of a relatively lower indexmaterial in order to better optically isolate the optical row waveguide25. A top layer 52 is provided on the top surface 47 of layer 35 forprotection of the underlying structures. In the case of FIG. 4 theentire structure is shown surrounded by air 55.

Integrated semiconductor waveguide optics and microcavities have raisedconsiderable interest for a wide range of applications, particularly fortelecommunications applications. The invention disclosed herein appliesthis technology to electronic displays. As stated previously, the energyexchange between cavities and waveguides is strongly dependent on thespatial distance. Controlling the distance between waveguides andmicrocavities is a practical method to manipulate the power coupling andhence the brightness of a pixel 10 or sub-pixel (11–13).

An ideal resonator or cavity has characteristics of high quality factor(which is the ratio of stored energy to energy loss per cycle) and smallmode volume. Dielectric micro-sphere and micro-toroid resonators havedemonstrated high quality factors. Micro-cavities possess potential toconstruct optical resonators with high quality factor and ultra-smallmode volume due to high index-contrast confinement. Small mode volumeenables small pixel 10 or sub-pixel (11–13) dimensions, consistent withthe requirements of a high resolution display. A MEMS device structurefor affecting the amount of light 20 coupled into a light emittingresonator 30 is shown in FIG. 5. FIG. 5 is an enlarged cross-sectionalview of the optical waveguide showing the electrode geometry, fieldlines 46, and resulting downward electrostatic force 44 for affectingthe power coupling change. MEMS actuators using electrostatic forces inthis instance, move a waveguide to change the distance h, shown in FIG.7A between a resonator and the optical row waveguide 25, resulting in awide tunable range of power coupling ratio by several orders ofmagnitude which is difficult to achieve by other methods. Based on thismechanism, the micro-disk/waveguide system can be dynamically operatedin the under-coupled, critically-coupled and over-coupled condition.

In high-Q micro-resonators, varying the gap spacing or distance h,between the waveguide and the micro-disk or micro-ring resonator bysimply a fraction of a micron leads to a very significant change in thepower transfer to the light emitting resonator 30 from the optical rowwaveguide 25. FIG. 6 is an enlarged perspective view of the display ofFIG. 1 showing a light emitting ring resonator 30; optical waveguide 25,and triggering electrodes 24 _(1-n) and 28. As shown in FIG. 6, asuspended waveguide is placed in close proximity to the micro-ring ormicro-toroid light emitting resonator 30. The initial gap (not shown)(˜1 μm wide) is large so there is no coupling between the waveguide andthe resonator. Referring to FIG. 6, the suspended optical row waveguide25 can be pulled towards the micro ring resonator by four electrostaticgap-closing actuators, the electrodes 23 and 28. Therefore, the couplingcoefficient can be varied by applied voltage. For high index-contrastwaveguides, the coupling coefficient is very sensitive to the criticaldistance. 1-um displacement can achieve a wide tuning range in powercoupling ratio, which is more than five orders of magnitude. Typically,the radius of micro-ring resonator is 10 μm and the width of waveguideis 0.7 μm. But these sizes may vary depending upon the display type andapplication. In FIG. 6 the optical waveguide 25 is shown displaceddownward so as to affect a maximum power transfer to the light emittingresonator 30.

FIG. 7A is an enlarged cross-sectional view of the display of FIG. 6,which shows the location of a MEMS device used to control the pixelintensity. The area surrounding the optical row waveguide 25 and thelight emitting ring resonator 30 has been etched back to expose the topsurfaces 48 to air 55. The optical row waveguide 25 is aligned to theedge of the light emitting resonator 30 and vertically displaced topreclude a high degree of coupling. The waveguide 25 is electricallygrounded and actuated by a pair of triggering electrodes 24 _(1-n)associated with a single resonator 30 and electrode 28, which forms anelectro-coupling region 58. Due to the electrostatic force, thewaveguide is pulled downward toward the light emitting resonator 30,resulting in the decreased gap spacing, h. The optical row waveguide 25is shown in the rest position d in FIG. 7A. In FIG. 7A, the distancebetween the optical row waveguide 25 and the light emitting ringresonator 30 is large; coupling of light into the light emittingresonator 30 is precluded and there is no light emission from the pixel.

Initially, in the absence of the application of the control voltage, theoptical row waveguide 25 is separated from the light emitting resonatorby a distance significantly greater than the critical distance “h_(c)”31 (see FIG. 7C) and hence there is no light emission from the lightemitting resonator 30. In FIG. 7B, the vertical distance d′ is shownwhere there exists a degree of coupling between the optical rowwaveguide 25 and the light emitting ring resonator 30, and hence lightemission from the pixel occurs. By varying the distance d′, theintensity of the light emission from the pixel can be varied in acontrollable manner. In FIG. 7C, the distance d″ is shown thatcorresponds to the displacement of the optical row waveguide 25necessary to place the optical row waveguide 25 at the critical couplingdistance h_(c) and thereby optimize power coupling. This configurationwill produce the maximum emitted light intensity from the pixel. Notethat light emitting resonator is shown with a roughened surface 60; thiswill be discussed below. The optical row waveguide can be fabricatedfrom silicon appropriately doped to provide electrical conductivity.Alternatively, the optical row waveguide can be fabricated from otheroptically transparent conductive materials such as polymers that meetthe optical index of refraction requirement disclosed above.

In the embodiment shown in FIG. 7C, the light emitting resonator 30 isshown spaced the critical distance 31, h_(c) from the optical rowwaveguide 25. Excitation light 20 is emitted from top roughened surface60 of the light emitting resonator 30, which causes the light emittingresonator to leak light and become visible to a viewer. As shown in FIG.7C, a light emitting layer 49 is placed within the light emittingresonator. This layer 49 contains photo-luminescent species orlumiphores 65 that absorb the pump or excitation light 20 and via theluminescence processes discussed above, produce the visible lightdirected to the viewer. The wavelength of the light produced in theemitting layer 49 is determined by the material composition aspreviously disclosed. The light emitting layer 49 may be formed on thetop surface of the light emitting resonator 30 as well as placed withinthe internal structure of the light emitting resonator as is shown inFIG. 7C. FIG. 7C shows the emitting layer 49 displaced vertically fromthe bottom surface 39 of light emitting resonator 30.

FIG. 8 is an enlarged cross-sectional view of the resonator elementsshowing an alternative embodiment for the light-emissive resonator 30.In this embodiment the lumiphores 65 are shown uniformly distributedwithin the light emitting resonator 30.

FIG. 9 is an enlarged top plan view showing an alternative resonatorembodiment in the form of a disk. The critical distance “h_(c)” 31 isshown as well as the light emitting disk 67 resonator. A number ofstructures have been demonstrated for the resonator element includingring, disk, elliptical and racetrack or oval structures. The coupling ofoptical power into such structures is well known to those skilled in theart. The use of such structures as light emitting resonators isconsidered within the scope of this invention.

The present invention allows for the individual addressing of individualpixel elements, such as resonators 30. The individual allows for animproved performance of the device. The individual addressing of thepixel elements of the present invention allows quicker refreshing ratesas only those resonators that need changing are accessed therebyminimizing the potential for flickering of the display image. Inaddition, individually addressing the resonators 30, the possibility ofactivating undesired resonators is minimized. While the presentapplication has shown one way of individually addressing the electrodesassociated with a single pixel element, any suitable technique may beutilized.

The invention has been described with reference to a preferredembodiment; however, it will be appreciated that variations andmodifications can be affected by a person of ordinary skill in the artwithout departing from the scope of the invention. In particular, it iswell known in the art that the optical row waveguide 25 can be placedadjacent to the light emitting resonator 30 in the same horizontalplane, and tuned for power transfer by affecting a lateral, that isin-plane or horizontal displacement, rather than the verticaldisplacements depicted above. Additionally, it may be advantageous toplace the optical row waveguide 25 above the light emitting resonator 30adjacent to the periphery of the light emitting resonator 30. In thislatter case the electro-coupling region 58 would be placed verticallyabove the edge of the light emitting resonator 30 and power transferaffected by a vertical displacement of the optical row waveguide 25relative to the top surface of the light emitting resonator 30. Manyother such variations are possible and considered within the scope ofthis invention.

It is to be understood that further modification made be made withoutdeparting from the present invention, the present invention be definedby the claims set forth herein.

1. A display device, comprising: a. a support substrate; b. a pluralityof light emitting resonators placed in a matrix on said supportsubstrate forming a plurality of rows and columns of said light emittingresonators; c. a plurality of light waveguides positioned on saidsubstrate such that each of said light emitting resonators is associatedwith an electro-coupling region with respect with to one of saidplurality of light waveguides; d. a deflection mechanism for causingrelative movement between a portion of at least one of said plurality oflight waveguides and said associated light emitting resonator so as toindividual control when each of said light emitting resonator is in saidelectro-coupling region, said deflection mechanism comprises pairs ofelectrodes associated with each of said plurality of light emittingresonators and an triggering electrode associated with each of saidpairs of electrodes for selecting deflecting a portion of said waveguideassociated with one of said plurality of light emitting resonatorswhereby when a voltage is applied across said pair of electrodes andsaid triggering electrodes associated with said selected resonator thatfield is produced which caused said at least one waveguide to move intosaid electro-coupling region; and e. a light source associated with eachof said plurality of light waveguides for transmitting a light alongsaid plurality of light waveguides for selectively activating each ofsaid light emitting resonators when positioned within saidelectro-coupling region.
 2. A display device according to claim 1wherein said light source comprises an infrared light source.
 3. Adisplay device according to claim 2 wherein said infrared light sourcecomprises a laser infrared light source.
 4. A display device accordingto claim 1 wherein said light source comprises a light emitting diode.5. A display device according to claim 1 wherein said plurality of lightemitting resonators comprises light emitting resonators.
 6. A displaydevice according to claim 5 wherein said light emitting resonators havea roughened surface.
 7. A display device according to claim 6 whereinsaid light emitting resonators comprises an upconverting phosphor.
 8. Adisplay device according to claim 6 wherein an emissive coating isprovided over said roughened surface.
 9. A display device according toclaim 1 wherein an overcoat is provided over said plurality of lightemitting resonators and light waveguides.
 10. A display device accordingto claim 1 wherein a control mechanism is provided for controlling theamount of voltage across said pair of electrodes and said triggeringelectrodes for controlling the distance in which said at least onewaveguide moves into said electro-coupling region so as to control theamount of emission from said associated light emitting resonator.
 11. Adisplay device according to claim 1 wherein said plurality of lightemitting resonator are grouped into sets wherein in each of said lightemitting resonators emit a different color.
 12. A display deviceaccording to claim 1 wherein at least one of said plurality of lightemitting resonators have a ring shaped.
 13. A display device accordingto claim 1 wherein at least one said plurality of light emittingresonators is disc shaped.
 14. A method for controlling visible lightemitting from a display device having plurality of light emittingresonators placed in a pattern forming a plurality of rows and columnsand a plurality of wave light guides positioned so that each of saidlight emitting resonators is positioned adjacent one of said pluralityof wave light guides; comprising the steps of: a. providing a lightsource associated with each of said plurality of light waveguides fortransmitting a light along said associated light waveguide; b. providingdeflection mechanism for causing selective individual relative movementbetween a portion of at least one of said plurality of light waveguidesand one of said associated light emitting resonator so as to selectivelycontrol when each of said light emitting resonator is in saidelectro-coupling region; and c. selectively controlling emission ofvisible light from said plurality of light emitting resonators bycontrolling said deflection mechanism and light source such that whensaid light emitting resonator in said electro-coupling region and alight is transmitted along said associated light waveguide said emissionof visible light will occur; and d. a control mechanism is provided forcontrolling the amount of voltage across said pair of electrodes andsaid triggering electrodes so as to control the distance in which saidat least one waveguide moves into said electro-coupling region so as tocontrol the amount of emission from said associated light emittingresonator.
 15. The method according to claim 14 wherein deflectionmechanism for causing relative movement comprises pairs of electrodesassociated with each of said plurality of light emitting resonators andan triggering electrode associated with each of said pairs of electrodesfor selecting deflecting a portion of said waveguide associated with oneof said plurality of light emitting resonators whereby when a voltage isapplied across said pair of electrodes and said triggering electrodesassociated with said selected resonator that field is produced whichcaused said at least one waveguide to move into said electro-couplingregion.
 16. The method according to claim 14 wherein said light sourcecomprises an infrared light source.
 17. The method according to claim 16wherein said infrared light source comprises a laser infrared lightsource.
 18. The method according to claim 14 wherein said light sourcecomprises a light emitting diode.
 19. The method according to claim 14wherein said plurality of light emitting resonator are grouped into setswherein in each of said light emitting resonators emit a differentcolor.
 20. The method according to claim 14 wherein at least one of saidplurality of light emitting resonators have a ring shaped.
 21. Themethod according to claim 14 wherein at least one said plurality oflight emitting resonators is disc shaped.